One month into a simulated space mission, a team of "gastronauts" in Hawaii is already figuring out what to have for dinner on Mars. It's thumbs up for wraps and vegetables, even when the vegetables are dehydrated or freeze-dried. It's thumbs down for pre-prepared meat dishes and most sugary drinks. But Tang is a hit, just as it was for astronauts 50 years ago.

HI-SEAS is about more than food: In addition to the taste tests, the crew members are playing with robo-pets, coping with the disconnects that a Mars expedition would encounter, and even trying out odor-resistant underwear. "Two crew members have been wearing the same exercise shirt for five weeks now without any problem, so we suspect they might have been treated,” Angelo Vermeulen, the crew commander for the simulation, told NBC News in an email co-written with other crew members.

Simulating MarsThe HI-SEAS mission is part of a three-year, $947,000 NASA grant that also covers a bed-rest study in Texas. For most of the time, the gastronauts are confined to a domed habitat placed at the 8,000-foot level on Hawaii's Mauna Loa volcano. If crew members go outside, they have to wear mock spacesuits. And as the mission continues, communications between the habitat and the outside world will be delayed 20 minutes each way to simulate the light-travel time between Mars and Earth.

Not everyone likes the concept. In March, Sen. Rand Paul, R-Ky., made fun of HI-SEAS as an example of government waste. "For any of you college students looking for jobs, Uncle Sam's got a job for you," he said at the Conservative Political Action Conference in Washington. "The pay's $5,000, all expenses paid. The study is in Hawaii. But the requirements are onerous. Only a few can qualify. You have to like food."

In fact, not one of the crew members is a college student: Vermeulen is a space researcher and artist. The other participants are materials scientist Yajaira Sierra-Sastre, roboticist Simon Engler, geologist Sian Proctor, biologist Oleg Abramov and journalist Kate Greene. These six were selected from about 700 applicants.

Food ... in ... space!The project is one of several initiatives NASA is funding to find out what works best as a long-duration diet. Just last week, the space agency firmed up a $125,000 contract with a Texas company to work on a 3-D printer for space food. Johnson Space Center has its own lab that works on orbital menus, and astronauts on the International Space Station have tried growing their own lettuce. Experts say astronauts on Mars will probably grow their own food as well.

Astronauts sometimes complain about the bland, boring menus they face in space — and that's the main focus for the HI-SEAS experiment: The crew is trying out the typical just-add-water meals served on the space station, and comparing them with meals that are created from a pantry of bulk ingredients, plus canned, dehydrated and freeze-dried foodstuffs.

"The advantages of using pre-prepared meals is that they’re less time-consuming and less stressful. Hardly any thinking needed." Vermeulen wrote. "But of course, they’re also less culinarily satisfying."

He and his crewmates use the dehydrated and freeze-dried vegetables whenever they can. "Wraps work really well: We combine tortillas, different vegetables, Velveeta cheese and sausage or canned fish. ... This is actually in line with the success of tortillas at the ISS," Vermeulen wrote.

The freeze-dried meat is a different story. A pre-prepared dish called "Kung Fu Chicken" is particularly awful: "The texture of the meal could be best described as 'slimy,'" Vermeulen wrote. No wonder the astronauts complain.

The HI-SEAS crew quickly went through their supply of Tang, but the other sugared drinks have hardly been touched. Now they're mostly drinking water, tea and coffee.

Not by bread aloneThe crew's other research projects focus on different aspects of long-duration missions: A test of odor-resistant exercise wear serves as a practice run for an experiment that NASA is planning on the space station. Some of the togs are treated with antimicrobial agents, while others are left untreated. The crew members' mission is to wear the clothing for their workouts until they can't stand it any longer.

The test subjects aren't supposed to know which clothes are which, but they think they can tell the difference. "One of the crew members told us he was very impressed and that it was by far the best exercise shirt that he has used," Vermeulen wrote. The crew is also testing antimicrobial underwear, socks, gloves, towels and bed linens for Cupron, the company that makes them.

Meanwhile, Engler is experimenting with robotic pets to see whether a needy, an assertive or a passive robo-personality is a better fit for space companionship. "It has been well-established that domestic pets can provide a great deal of stress relief and create emotional bonds with their owners. At this time it is not practical for domestic animals to accompany long-term space missions, so it is of interest to examine the potential of providing robotic companions," Vermeulen's email explained.

The HI-SEAS simulation also provides an opportunity to study group dynamics for long-duration space missions, including a phenomenon called crew-ground disconnect. "It's the perception by the crew that the mission support team doesn't understand what they're going through, are overscheduling them and aren't as supportive as they want them to be," said Kim Binsted, a HI-SEAS project leader at the University of Hawaii at Manoa. "That certainly has reared its head a couple of times."

So far, there have been no signs of friction between the crew members, but what about signs of affection? Vermeulen's answer to the inevitable question about sex provided no grist for gossip: "We’re actually getting along fine and keep professional relationships," he wrote.

Binsted said the Hawaiian habitat isn't that conducive to romantic flings, due to the lack of privacy as well as the fact that the Internet lets crew members stay in touch with their loved ones in the outside world. The dynamics may be different for an actual Mars crew during a years-long mission, however. That's a question hanging over NASA's vision for Red Planet exploration.

To answer such questions, researchers plan to push the envelope for long-duration missions. Binsted said NASA recently approved another $1.2 million in funding for HI-SEAS over the next three years, with the goal of building up to a yearlong simulation. "The 12-month mission, we think, is going to line up time-wise with the 12-month mission on the International Space Station in 2015," Binsted said.

That means a future HI-SEAS crew could play a part in a real-life orbital experiment. "It's looking as if our mission will be a control experiment of a sort for the space station," Binsted said.